A British couple held captive for more than a year by Somali pirates said they were "skinny and bony" but otherwise fine today after a substantial ransom was paid to secure their release.

Taken hostage after pirates boarded their yacht during what was meant to be the retirement trip of a lifetime, Paul and Rachel Chandler, 61 and 56, from Tunbridge Wells, landed in the Kenyan capital of Nairobi on a charter flight, and were taken to a "place of safety" by diplomats from the British high commission.

Earlier, the pirate gang holding them had ended their terrifying 388-day ordeal by handing them to officials in Adado, central Somalia. An agreement to release them was finally sealed last week with the payment of the second part of a ransom reported to have totalled about $800,000 (£500,000).

"We're fine, we're rather skinny and bony but we're fine," Paul Chandler told the BBC in Adado before flying on to the capital, Mogadishu, for a brief press conference at the presidential palace.

Looking painfully thin but smiling broadly, Rachel Chandler told reporters: "We're happy to be alive, happy to be here, desperate to see our family and friends, and so happy to be amongst decent, everyday people, Somalis, people from anywhere in the world who are not criminals, because we've been a year with criminals and that's not a very nice thing to be doing."

The Chandlers' family refused to comment on how their freedom was negotiated, saying only that common sense had "finally prevailed". In a statement, they said: "The family believes it would be irresponsible to discuss any aspect of the release process as this could encourage others to capture private individuals and demand large ransom payments, something that we are sure none of us wants."

There were reports tonight that the deal to finally release the Chandlers was brokered by a London taxi driver of Somali origin. Minicab driver Dahir Abdullahi Kadiye, who splits his time between his wife and children in Leytonstone, east London, and Somalia, told Channel 4 News that he had taken on the role six months ago because his children had told him they felt ashamed at school when they saw the Chandlers' appeals for help.

David Cameron described the couple's release as "tremendous news", adding: "Their long captivity is over at last. We will ensure that they are reunited with their family as quickly as possible." He added: "I unreservedly condemn the actions of those that held the Chandlers for so long. Kidnapping is never justified."

Foreign secretary William Hague said the British government would never pay ransoms: "We do not pay ransom or make significant concessions to hostage takers."

The Chandlers, who retired early to sail around the world in their 38ft yacht, the Lynn Rival, were kidnapped in the early hours of 23 October last year in the Indian Ocean between the Seychelles and Tanzania. The Royal Navy located them as they were being taken to Somalia, and a supply vessel was sent to intercept them. But though they could see the Chandlers, the crew could not stop them being transferred to a pirate mothership and on to land. The navy later had to defend its actions after it put out a misleading account of the incident.

Paul Chandler, who spent much of the early part of his captivity separated from his wife, said they had been told only two days before that they were to be released.

"We were told on Friday in a way which gave us some confidence to believe it. Otherwise we'd been told we'd be released in 10 days almost every 10 days for the past nine months. So we'd taken all these suggestions with a pinch of salt."

Asked if he had felt their lives had been in danger during captivity, he said: "That's something we'll talk about later, but we were not really directly endangered by the gang, after the initial seizure." Giving a hint of the ordeal the pair had undergone, Rachel Chandler described the moment that the pirates had tried to separate her from her husband. "They decided to separate us and we were very distraught," she said. "We were very frightened and refused to be separated and we were beaten as a result and it was very traumatic."

The Chandlers' captivity was unusually long due to difficulties in raising a ransom and deciding on a negotiating team. It is understood that they were close to being released earlier this year after a ransom of about $400,000 was paid, but the deal was aborted at the last moment. The Somali government and diaspora groups also tried to help, unsuccessfully.

The British government has a policy not to pay ransoms or make "substantive concessions" to hostage takers or kidnappers, and was unable to offer financial help. A Foreign Office spokeswoman said that no "operational details" of the Chandler episode would be released.

The Chandlers spent most of their captivity been shifted around Somalia's arid central region. Both suffered health problems at various times, and will receive a thorough medical checkup in Nairobi before returning to the UK. Despite his ordeal, Paul Chandler said that "ideally" he would like to get back to sea soon.

Patrols by more than 30 warships that form part of the international anti-piracy mission off Somalia have decreased the number of successful attacks on foreign ships, but have not deterred hijack attempts, which are occurring ever further from the Somali coast. Today the Navy ship RFA Port Victoria intercepted a broken-down pirate ship near the Seychelles, with ten armed pirates on board.